Early-life sugar consumption affects the rat microbiome independently of obesity

Abstract

Background: The gut microbiome has been implicated in various metabolic and neurocognitive disorders and is heavily influenced by dietary factors, but there is a paucity of research on the effects of added sugars on the gut microbiome. Objective: With the use of a rodent model, our goal was to determine how added-sugar consumption during the juvenile and adolescent phase of development affects the gut microbiome. Methods: Forty-two juvenile male Sprague-Dawley rats [postnatal day (PND) 26; 50-70 g] were given access to 1 of 3 different 11%-carbohydrate solutions designed to model a range of monosaccharide ratios commonly consumed in sugarsweetened beverages: 1) 35%fructose:65%glucose, 2) 50% fructose:50% glucose, 3) 65%fructose:35%glucose, and 4) control (no sugar). After ad libitum access to the respective solutions for the juvenile and adolescent period (PND 26-80), fecal sampleswere collected for next-generation 16S ribosomal RNA sequencing and multivariate microbial composition analyses. Energy intake, weight change, and adiposity index were analyzed in relation to sugar consumption and the microbiota. Results: Body weight, adiposity index, and total caloric intake did not differ as a result of sugar consumption. However, sugar consumption altered the gut microbiome independently of anthropometric measures and caloric intake. At the genus level, Prevotella [linear discriminant analysis (LDA) score = -4.62; P < 0.001] and Lachnospiraceae incertae sedis (LDA score = 23.01; P = 0.03) were reduced, whereas Bacteroides (LDA score = 4.19; P < 0.001), Alistipes (LDA score = 3.88; P < 0.001), Lactobacillus (LDA score = 3.78; P < 0.001), Clostridium sensu stricto (LDA score = 3.77; P < 0.001), Bifidobacteriaceae (LDA score = 3.59; P = 0.001), and Parasutterella (LDA score = 3.79; P = 0.004) were elevated by sugar consumption. No overall pattern could be attributable to monosaccharide ratio. Conclusions: Early-life sugar consumption affects the gut microbiome in rats independently of caloric intake, body weight, or adiposity index; these effects are robust across a range of fructose-to-glucose ratios.